As shown in FIG. 3, a direct current motor usually has two, four or six magnets 92 received in a housing 90. The magnets 92 are generally adhered within the housing 90 by adhesive materials. During operation, heat will be generated within the motor and the temperature within the motor will be increased so that the quality and the property of the adhesive materials will be changed and so that the magnets can not be stably retained in place which may cause the failure of the direct current motors.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional direct current motors.